
#ifdef ONLINE_JUDGE
    #include<stdio.h>
    #define INPUT stdin
    int main() {
#else
    #include"header.h"
    #define INPUT fptIn
    int acm_10071() {
        printf("--ACM 10071 begin here--\n");
        FILE *fptIn = fopen("Resource/acm_10071.txt","r");
        if ( fptIn == NULL )//Distinguish the fptInIn file is load success.
        {
            printf("File acm_10071.txt load fail.\n");
            printf("Program will exit.\n");
            return EXIT_FAILURE;
        }

#endif
    int v, t;
    while (fscanf(INPUT," %d %d", &v, &t) == 2) {
        printf("%d\n", 2 * v * t);
    }
    #ifndef ONLINE_JUDGE
        printf("--ACM 10071 end here--\n");
        fclose(fptIn);
    #endif
    return 0;
}
/*
   #    Problem                              Verdict    Language   Run Time       Submission Date 
8007769 10071 Back to High School Physics    Accepted     ANSI C      0.020      2010-05-31 10:22:11 
 */
